The folding mechanism of larger model proteins: role of native structure.
AUTOR(ES)
Dinner, A R
RESUMO
The folding mechanism of a 125-bead heteropolymer model for proteins is investigated with Monte Carlo simulations on a cubic lattice. Sequences that do and do not fold in a reasonable time are compared. The overall folding behavior is found to be more complex than that of models for smaller proteins. Folding begins with a rapid collapse followed by a slow search through the semi-compact globule for a sequence-dependent stable core with about 30 out of 176 native contacts which serves as the transition state for folding to a near-native structure. Efficient search for the core is dependent on structural features of the native state. Sequences that fold have large amounts of stable, cooperative structure that is accessible through short-range initiation sites, such as those in anti-parallel sheets connected by turns. Before folding is completed, the system can encounter a second bottleneck, involving the condensation and rearrangement of surface residues. Overly stable local structure of the surface residues slows this stage of the folding process. The relation of the results from the 125-mer model studies to the folding of real proteins is discussed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=38675Documentos Relacionados
- Folding of Polypeptide Chains in Proteins: A Proposed Mechanism for Folding
- Contribution of cotranslational folding to the rate of formation of native protein structure.
- Evidence for a controlling role of water in producing the native bacteriorhodopsin structure.
- Antigenicity and native structure of globular proteins: low frequency of peptide reactive antibodies.
- Processing of the initiation methionine from proteins: properties of the Escherichia coli methionine aminopeptidase and its gene structure.